Because of environmental pollution, the frequency of acid rain is increasing. In rural areas and small towns in China, many ancient buildings are masonry structures that are easily corroded by acid rain. Because of the poor seismic performance of masonry structures subjected to acid rain, research on these structures corroded by acid rain has become increasingly important. In this study, we designed four brick walls with common characteristics and tested them with a series of 0, 100, 200, and 300 corrosion cycles of acid rain. Then, using a low reversed cyclic loading test, we obtained the hysteresis curve of the four brick walls under these corrosion cycles. Based on the three-spring element model combined with the Lu Xinzheng-Qu Zhe restoring force model, we used the finite element software Marc to simulate the response of the brick walls. Our experimental results proved that the three-spring element model can accurately predict the hysteretic properties of masonry structures. To verify the rationality of using the three-spring element model to simulate the whole structure, we used it to construct a finite element model of a teaching building for modal analysis and compared it with the ABAQUS modal analysis results of previous research. Our results show that the three-spring element model can better reflect basic dynamic structural characteristics and satisfy requirements for nonlinear earthquake analysis. We also summarize domestic and overseas drift allowance angles of different damage states combined with our experimental results and China's national code to demarcate appropriate drift allowance angles. We used 15 seismic waves from the ATC-63 project to perform an incremental dynamic analysis of structures and to obtain seismic vulnerability curves under different corrosion cycles. Based on our analysis of the failure probability for different structural damage states from small, medium, and large earthquakes, acid rain can seriously affect structural mechanical properties and significantly reduce seismic performance.